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Re: how to delete HD partitions screwed up by DOS' fdisk



Peter Evans wrote:
[Hector Akamine:]
> > I just want to delete everything and start from scratch but
> > I don't know how to delete the partitions
>
> Get a friend with Win98 or even (horrors!) WinME to make you an
> "emergency diskette" (or whatever it's called in ME).

Start with that, but also download the "zap" program from IBM.  (The
download is intended for purchasers of IBM disk drives, but it didn't ask
for verification when I downloaded and used it, though sometimes I used it
on IBM disk drives anyway :-)  Of course you'll need a working computer to
download, unpack, and copy it to the emergency diskette.  This zeroes out
the MBR, similar to the Linux command that someone else gave in this thread,
but it runs in the real mode environment from booting a
DOS/Lose95/Lose98/etc diskette so you don't have to reinstall Linux to do
it.

> You ought to be
> able to run FDISK off that, and whatever FDISK's other faults I think
> it's pretty good at destroying what it sees.

It isn't.  Here are three counterexamples:

If you want to delete a non-DOS logical drive from inside the extended
partition, it won't let you.  It will let you delete a non-DOS primary
partition but that only accomplishes part of what Akamine-san needs.

If you don't want to delete a non-DOS logical drive from inside the extended
partition, then sometimes it will.  For example, if you have an NTFS logical
drive followed by a DOS logical drive, you tell it to delete the DOS logical
drive, it prompts for details of the DOS logical drive and verifies them,
then it deletes the NTFS logical drive which you wanted to keep but it
leaves the DOS logical drive intact.  You thought Microsoft only hated Linux
because that's what they do to Linux logical drives?  Well they do, but
Microsoft hates Microsoft just as much.

According to one or two Microsoft knowledge base articles, when FDISK is
deleting a non-DOS partition, FDISK assumes that the ending point of the
partition is at or below the 8GB point.  So depending on whether the
partition started before or after that point, I think the damage can range
from moderate to severe.  According to Microsoft's tech support, Microsoft
will not allow customers or even OEMs (computer manufacturers who force
customers to buy broken Windows programs together with their computers) to
download versions of FDISK in which Microsoft fixed this particular bug.

I think that FDISK can delete all partitions pretty reliably in some cases:
If all of the partitions were created by FDISK in the first place, and if
the partitions don't overlap (i.e. you didn't use Windows 95 OSR2 FDISK on a
SCSI drive, etc.), if the partitions haven't become corrupted by some other
broken Windows feature or virus etc., then you can probably do it.

> Alternatively (since you want Win2K anyway), you could just install
> Win2K and repartition as part of the installation process (if it's
> offered as part of this process, and I think it is).

It is offered, but I think the partition table has to be valid (or have an
MBR that is already zeroed) at that stage.


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